Presently, methods for function generation typically employ analog nonlinear amplifyingcircuits or digital computational hardware to perform an approximation algorithm. For analog square root extraction, usually some form of multiplier circuit in a feedback arrangement is used. The accuracy of the analog function generator is limited by circuitry errors and drifts unless elaborate means are utilized to compensate for same. Such means are typically very expensive to implement. As for digital techniques for function generation, the accuracy of such techniques is generally determined by the word size being processed so that a high degree of accuracy requires a large word size which, in turn, requires extensive circuitry to implement. In addition, the interfacing of the sensor and output driver circuitry requires additional circuitry which increases the overall size of the system and introduces more inaccuracies therein. In view of the foregoing, it is apparent that for transmitter applications where small size and low power consumption are required, the aforementioned conventional techniques are not appropriate.
Because of inherent problems associated with the prior art, it has become desirable to develop a relatively simple and inexpensive highly accurate function generator for extracting the square root of an input signal.